Back to results
US 7,731,670 B2Granted
Controller for an assistive exoskeleton based on active impedance
AssigneesHonda Motor Co., Ltd., Northwestern University
InventorsGabriel Aguirre-Ollinger, Ambarish Goswami, J. Edward Colgate, Michael A. Peshkin
Life of this patent
Estimating the term…
Abstract
A system and method are presented to provide assist to a user by means of an exoskeleton with a controller capable of making the exoskeleton display active impedance. The exoskeleton assists the user by reducing the muscle effort required by the user to move his or her extremities. In one embodiment, a single-degree-of-freedom (1-DOF) exoskeleton assists a user with single-joint movement using an active impedance controller. In another embodiment, a multiple-degree-of-freedom (multi-DOF) exoskeleton assists a user with multiple-joint movement using an active impedance controller.
Claims14
A method for controlling an actuator of an exoskeleton with a controller, comprising:
- the controller receiving a desired mechanical impedance function of the exoskeleton, the desired mechanical impedance function comprising a desired relationship between forces applied to the exoskeleton and resulting angular velocities of the exoskeleton at various frequencies;
- the controller receiving a measured interaction force, wherein the measured interaction force represents an interaction between the exoskeleton and a limb segment of a user wearing the exoskeleton;
- and
- controlling a kinematic trajectory of the actuator with the controller based on the measured interaction force using impedance control to implement the desired mechanical impedance function of the exoskeleton,
- the desired mechanical impedance function of the exoskeleton being an active impedance function that causes the exoskeleton to be assistive to the user wearing the exoskeleton by reducing a muscle torque required to move the limb segment, the desired mechanical impedance function comprising a negative exoskeleton impedance component, wherein the negative exoskeleton impedance component is determined by estimating a limb impedance component of the limb segment of the user and by negatively scaling the estimated limb impedance component based on a degree of reduction of the muscle torque required to move the limb segment.
2 more elements
A method for controlling an actuator of an exoskeleton with a controller, comprising:
- the controller receiving a desired mechanical impedance function of the exoskeleton, the desired mechanical impedance function comprising a desired relationship between forces applied to the exoskeleton and resulting angular velocities of the exoskeleton at various frequencies;
- the controller receiving a measured angular velocity of a limb segment of a user wearing the exoskeleton;
- and
- controlling a force of the actuator with the controller based on the measured angular velocity using impedance control to implement the desired mechanical impedance function of the exoskeleton,
- the desired mechanical impedance function of the exoskeleton being an active impedance function that causes the exoskeleton to be assistive to the user wearing the exoskeleton by reducing a muscle torque required to move the limb segment, the desired mechanical impedance function comprising a negative exoskeleton impedance component, wherein the negative exoskeleton impedance component is determined by estimating a limb impedance component of the limb segment of the user and by negatively scaling the estimated limb impedance component based on a degree of reduction of the muscle torque required to move the limb segment.
2 more elements
A controller for controlling an actuator of an exoskeleton, the controller comprising:
- a processor;
- and
- a computer-readable storage medium storing computer program modules executable on the processor, the modules configured for:
- receiving a desired mechanical impedance function of the exoskeleton, the desired mechanical impedance function comprising a desired relationship between forces applied to the exoskeleton and resulting angular velocities of the exoskeleton at various frequencies;
- receiving a measured interaction force, wherein the measured interaction force represents an interaction between the exoskeleton and a limb segment of a user wearing the exoskeleton;
- and
- controlling a kinematic trajectory of the actuator based on the measured interaction force using impedance control to implement the desired mechanical impedance function of the exoskeleton,
- wherein the desired mechanical impedance function of the exoskeleton being an active impedance function that causes the exoskeleton to be assistive to the user wearing the exoskeleton by reducing a muscle torque required to move the limb segment, the desired mechanical impedance function comprising a negative exoskeleton impedance component, wherein the negative exoskeleton impedance component is determined by estimating a limb impedance component of the limb segment of the user and by negatively scaling the estimated limb impedance component based on a degree of reduction of the muscle torque required to move the limb segment.
5 more elements
A controller for controlling an actuator of an exoskeleton, the controller comprising:
- a processor;
- and
- a computer-readable storage medium storing computer program modules executable on the processor, the modules configured for:
- receiving a desired mechanical impedance function of the exoskeleton, the desired mechanical impedance function comprising a desired relationship between forces applied to the exoskeleton and resulting angular velocities of the exoskeleton at various frequencies;
- receiving a measured angular velocity of a limb segment of a user wearing the exoskeleton;
- and
- controlling a force of the actuator based on the measured angular velocity using impedance control to implement the desired mechanical impedance function of the exoskeleton,
- the desired mechanical impedance function of the exoskeleton being an active impedance function that causes the exoskeleton to be assistive to the user wearing the exoskeleton by reducing a muscle torque required to move the limb segment, the desired mechanical impedance function comprising a negative exoskeleton impedance component, wherein the negative exoskeleton impedance component is determined by estimating a limb impedance component of the limb segment of the user and by negatively scaling the estimated limb impedance component based on a degree of reduction of the muscle torque required to move the limb segment.
5 more elements
Dependencies are inferred from the claim text.